With an emphasis today on increasing vehicle fuel economy, cars and light trucks are being reduced in size where possible to help reduce the overall weight of the vehicle. In doing so, the space allowed for various systems in vehicles is also shrinking. This, in turn, requires that the various systems themselves must be reduced in size, typically by reducing the size of their individual parts within the various systems or by reconfiguring the assemblies of these systems to be more compact.
In the case of a drive mechanism for windshield wipers, this creates a desire to reduce the height of the traditionally "tall" double ball joint construction used for coupling a wiper motor crank lever to the two drive links in a drive-drive wiper system. This reduction in the overall size of the wiper system will thereby allow easier packaging of the wiper system into a vehicle as well as help to reduce weight.
An example of a "tall" double ball joint system is disclosed in U.S. Pat. 3,749,431 to Schmid. Schmid discloses a double ball joint design, but it is undesirably tall, thus requiring more space when mounted within the vehicle and increasing weight. Windshield wiper rods are mounted at the mid-point of each socket and a crank drive is mounted beyond the end of one of the sockets. Since the crank drive is on the end, it does not have the advantage of using a more compact connection arrangement to reduce the overall height of the double ball connector. Reducing the overall height allows for better packaging of the wiper system in the vehicle sheet metal, thus saving space and reducing weight.